1. Field of the Invention
The present invention relates to an image capturing device, and more particularly to a thin image capturing apparatus.
2. Brief Description of the Related Art
In some of present notebook computers available in the market, an image capturing device is installed at the top of a screen to capture images for communications or video records. As notebook computers tend to be developed with a light, thin, short and compact design and the pixel requirement of the image capturing device becomes increasingly higher, the thickness of a casing of the notebook computer can be as thin as 5 mm only, and the space for installing a 3 mega-pixel image capturing device (including a camera lens) is only 3.5 mm. As to the concurrent way of assembling image capturing devices, the overall thickness of the 3 mega-pixel image capturing device becomes greater and results in a bottleneck for assembling an image capturing device with a larger pixel value into a 3.5 mm-space, so that major manufacturers improve the packaging technology to overcome this problem with full commitment and dedication.
With reference to FIG. 20 for a conventional packaging structure 90 of an image capturing device, the packaging structure 90 comprises a light sensing element 900, a translucent plate 901, and a circuit substrate 902, wherein the translucent plate 901 includes a circuit 903 coupled to a signal output, electrically coupled to a contact point 904 of the light sensing element 900, and sealed with an adhesive 905, and another side of the translucent plate 901 is electrically coupled to the circuit substrate 902 to form the packaging structure 90. Compared with the packaging structure of an earlier stage, this packaging structure 90 has reduced the overall thickness, but when the camera lens 906 is installed onto the circuit substrate 902, the position of the camera lens 906 must be aligned precisely with a sensing area of the light sensing element 900. For a small discrepancy, poor images may result, and thus the packaging structure 90 must be calibrated manually for precisely installing the camera lens 906 at a correct position of the circuit substrate 902, and the operation is very troublesome and impractical.
With reference to FIG. 21 for another packaging structure 91 of a conventional image capturing device, the packaging structure 91 also comprises a light sensing element 910, a translucent plate 911, and a circuit substrate 912, wherein the circuit substrate 912 has an opening 913, and the translucent plate 911 is installed onto the light sensing element 910, and the light sensing element 910 is installed onto a side of the translucent plate 911 and attached onto the substrate 912 by an adhesive 914. Meanwhile, a solder pad 915 of the light sensing element 910 is electrically coupled to the circuit substrate 912. Now, the translucent plate 911 is situated inside the opening 913 of the circuit substrate 912 for reducing the overall thickness to constitute this packaging structure 91. Compared with the foregoing packaging structure 90, this packaging structure 91 has a smaller package size, but this packaging structure 91 still has the same problem as the foregoing packaging structure 90 that requires a manual calibration to precisely install the camera lens 916 onto circuit substrate 912, and thus both packaging structure 90 and packaging structure 91 have not been used in actual productions yet.
With reference to FIG. 22 for another packaging structure 92 of a conventional image capturing device, the packaging structure 92 also comprises a light sensing element 920, a translucent plate 921, a circuit substrate 922, and a heat dissipating substrate 923, wherein both light sensing element 920 and circuit substrate 922 are installed onto the heat dissipating substrate 923, and the circuit substrate 922 has an opening 924 for exposing the light sensing element 920, and the light sensing element 920 is electrically coupled to the circuit substrate 922 by a connecting wire 925, and the translucent plate 921 is installed onto two pads 926 and disposed at the top of the light sensing element 920, and a camera lens 927 is installed at the translucent plate 921 to constitute the packaging structure 92. However, this packaging structure 92 requires an additional installation of the heat dissipating substrate 923, so that the overall thickness of the packaging structure 92 is relatively large, and requires further improvements.
With reference to FIG. 23 for another packaging structure 93 of a conventional image capturing device, the packaging structure 93 comprises a light sensing element 930, a metal plate 931, and a circuit substrate 932, wherein the metal plate 931 is installed at the bottom of the circuit substrate 932, and the circuit substrate 932 has an opening 933, and the metal plate 931 is exposed from the bottom of the opening 93, and the light sensing element 930 is contained in the opening 933 and whose bottom is attached to the metal plate 931 bottom, and the light sensing element 930 and the circuit substrate 932 are electrically coupled by a gold wire 934. However, the metal plate 931 and the circuit substrate 932 are made of different materials, so that it is difficult to attach the metal plate 931 with the circuit substrate 932 due to the significantly different coefficients of thermal expansion. It is very often to see a separation of the metal plate 931 and the circuit substrate 932 caused by thermal expansion or a poor attachment. As a result, the light sensing element 930 and the circuit substrate 932 are displaced with respect to each other easily when they are shock or vibrated, and the fine gold wire 934 will be pulled or broken easily.